The Grande Dixence is the tallest gravity dam in the world! At 285m, built on the wild and raging waters of the Dixence river in Hérémence, the dam is a marvel of modern engineering and a must-see tourist attraction for adventure seekers. The 700m long dam collects meltwater from 35 glaciers in the canton of Valais. Thousands of workers concrete to build the dam over 5 years and create what has become an excellent source of renewable energy. Hike: starts at the Pavillon d'information Grande Dixence, 4.3km, 303m elevation gain, out&back, around 1h49min to complete.